Recent Developments in Potable Water Reuse

Abstract

Potable water reuse through the use of treated wastewater effluents has been practiced for more than 50 years. The majority of projects worldwide are characterized as indirect potable water reuse, where an environmental buffer (groundwater aquifer or surface water reservoir) provided retention, additional attenuation, and blending prior to use as drinking water. In order to protect public health, these projects have utilized different treatment processes and combina- tions to establish multiple barriers against microbial and chemical contaminants. Due to the advancements in environmental analytical chemistry and the recog- nition of contaminants of emerging concern occurring in reclaimed water that might exhibit adverse health effects, additional advanced treatment processes (including ozone, advanced oxidation, activated carbon) were implemented. With increasing reliability of advanced water treatment processes and operational experience over several decades, the role of the environmental buffer to provide treatment and retention time has been revisited in projects that came online during the last 10 years. Recent trends are favoring direct potable water reuse applications in particular in the USA and Southern Africa that might evolve as the new paradigm for drinking water augmentation using impaired source water. However, questions remain regarding proper protection of public health, reliabil- ity and degree of treatment, appropriateness and design of monitoring strategies, maintenance requirements, and cost. Keywords